1. Field of the Invention
The present invention relates to a liquid crystal display provided with a back light and, more particularly, to a supporting structure of a liquid crystal panel and a wiring structure for a light source of the back light.
2. Prior Arts
Generally, as shown in FIG. 8, an entire liquid crystal display comprises: a liquid crystal panel 50 in which a display material such as liquid crystal is held between two opposed substrates; a circuit board 51 which is disposed for driving the panel 50; an edge type lighting device (back light) 53 which is disposed at the rear (on the backside) of the liquid crystal panel 50 through a plastic frame 52; and an outer frame 54 covering these elements.
In the conventional liquid crystal display of above structure, for the purpose of supporting the liquid crystal panel 50 on the back light 53, stoppers 56 are disposed at four corners 55a, 55b, 55c and 55d of the plastic frame 52 forming an integral one unit with the plastic frame 52.
In the mentioned conventional liquid crystal display, a wiring section of the light source for the back light is arranged as described below. That is, as shown in FIG. 9a (perspective view in which outer frame 107 is omitted for the sake of easy understanding) and FIG. 9b (sectional view), the conventional liquid crystal display comprises: a light guide plate 101 having an illumination surface 1011A which is formed of a plane light-transmitting member composed of a lens film or the like on a front face portion 1011 thereof and having a subref lector composed of a reflection film on a back face portion 1014 and on a side end face portion 1013; a light source 103 which is disposed adjacent to a front end face portion 1012 of the mentioned light guide plate 101 and emits a light to be guided into the light guide plate 101; a liquid crystal panel 102 which is disposed on the front side of the illumination surface 1011A of the mentioned light guide plate 101 and controls the transmission of the light guided by the electric signal through the light guide plate 101; a main reflector 104 which is attached to the front end face portion 1012 of the mentioned light guide plate 101 by surrounding the mentioned light source; and a wiring section 105 for supplying a power to the mentioned light source. In the wiring section, a low voltage side wiring 105B was arranged insulatedly at the rear of the mentioned main reflector 104. The mentioned elements were all accommodated in the outer frame 107.
The light source 103 is lighted up by the power source supplied through the wiring section 105, and the illumination surface 1011A of the light guide plate 101 is illuminated with the light of the light source 103 from the rear of the liquid crystal panel 102. On the liquid crystal panel 102, the transmission of light at the portions corresponding to respective picture elements is controlled by electric signal, thereby depicting a required picture on the liquid crystal panel 102, and accordingly, the picture depicted on the liquid crystal panel 102 may be seen from the front side. The control signal is supplied from outside to the liquid crystal display 102 through the circuit board 106.
Since the conventional liquid crystal display is arranged as described above, in the aspect of supporting the liquid crystal panel, the stoppers 56 shown in FIG. 8 are formed at the time of forming the plastic frame 52, and at least 0.5 to 0.6 mm is required to secure a minimum thickness of the stoppers 56. Accordingly, when end face of the stoppers 56 is put in contact with the back side of the lamp, longitudinal dimension of the liquid crystal display is increased, and when internal face of the stoppers 56 is put in contact with the side end face of the lamp, lateral dimension of the liquid crystal display is increased. Furthermore, a space (thickness) for disposing the stoppers must be secured also on the opposite side of the lamp, and therefore dimensions of the liquid crystal display are increased as much as the lamp side.
In the aspect of wiring of the light source of the back light, as shown in FIGS. 9(a) and (b), since the insulated low voltage side wire 105B is arranged at the rear of the main reflector 104 for the power supply to the light source, a large dead space is produced round the low voltage side wire 105B, eventually resulting in the problem of large external dimensions of the entire liquid crystal display.